Integrated transcriptomics-proteomics analysis reveals the regulatory network of ethanol vapor on softening of postharvest blueberry

Fruit firmness is an important trait of postharvest blueberry, and ethanol vapor treatment has been shown to can retard blueberry softening by inhibiting the degradation of cell wall polysaccharides in our previous work. However, fruit softening is a complex process regulated by many factors. Here, the regulation mechanism of ethanol mediated delaying blueberry softening at the levels of mRNA and protein were explored with integrated transcriptomics-proteomics analysis. Results revealed that, 9158 differentially expressed genes (DEGs) and 1223 differentially expressed proteins (DEPs) were identified in the ethanol vapor-treated blueberry (E20) compared with the control (C20) at the 20th day of cold storage, 351 correlation molecules (DEG/DEP) were obtained through correlation analysis. Ethanol treatment reduced the overall metabolism level of blueberry, downregulated the gene expression of polygalacturonase, glucan-1,3-β-glucosidase and endoglucanase in carbohydrate metabolism pathway, and slowed down the degradation of cell wall polysaccharides such as pectin and cellulose; downregulated the gene expression of ACC oxidase, the key enzyme for ethylene synthesis, reduced the production of ethylene, reducing the ripening and softening effect of ethylene on the fruit, and then delayed the softening process of blueberry fruit. Collectively, ethanol vapor is a promising technology for retarding the softening of fruit and vegetables.